Major Jason Griffiths enlisted into The Junior Leaders Regiment, Royal Armoured Corps as a trombonist in Bovington, Dorset in September 1984 at the age of 16. After two years training he was assigned to the Band of The Queen's Own Hussars, who at the time were stationed in Hohne, North Germany. In January 1994, Major Griffiths was selected to attend the three-year Bandmaster Course at The Royal Military School of Music (RMSM), Kneller Hall in Twickenham. On completion of the course, he was appointed Bandmaster of The Band of The Parachute Regiment in April 1997, stationed in Aldershot Hampshire. He served for almost four years at the ‘PARAs’ before selection for assignment into The Household Cavalry. Following completion of the six-month Household Cavalry Equitation Course, Major Griffiths was appointed Bandmaster to The Band of The Blues & Royals (RHG/D) in March 2001 based in Windsor. In March 2003, Major Griffiths returned to RMSM and assumed the appointment of Training Design Warrant Officer where he assisted in the design of all courses for all Army Musicians.

In January 2005, he was commissioned and appointed Director of Music (DOM) of The King's Division Waterloo Band in Catterick, North Yorkshire. As a result of the MOD study ‘Future Army Structures’, Major Griffiths remained in Catterick and became the inaugural DOM to one of the newly formed Royal Armoured Corps bands, The Heavy Cavalry and Cambrai Band in June 2006. Following a total of three years in Catterick, Major Griffiths was appointed Deputy Chief Instructor in January 2008, again at RMSM and at the end of that year moved to HQ Corps of Army Music (CAMUS) and became desk Officer responsible for Career Management Policy and Recruiting for CAMUS. During this period, Major Griffiths spent five months on exchange to New Zealand where he served as DOM to their only Regular Army Band. In January 2011, Major Griffiths returned to the RHG/D Band, this time as the DOM. Following three years in Windsor, Major Griffiths was selected for assignment to The Army Personnel Centre in Glasgow and assumed the post of Staff Officer responsible for the Career Management of all CAMUS soldiers.

Maj Griffiths was delighted to assume the prestigious appointment of DOM of The Band and Bugles of The Rifles in February 2016. Highlights thus far include acting as the Senior DOM for the Massed Rifles Sounding Retreat on Horse Guards Parade in June 2016 and as the Principal DOM for The Royal Edinburgh Military Tattoo in August 2016